Once a nomura has grown, it becomes much bolder, though still quite skittish compared to other companions. As it matures, its colors slowly fade from black and yellow to beautiful iridescent blue and green. Their bodies never stop growing, getting longer and longer, though after their first year of life their growth slows to a crawl. At this stage, a magi is finally able to truly bond with their nomura, as it allows them to see and interact with it. It may take many years of careful trust-building, but eventually a magi may be able to glimpse the nomura's magic, and perhaps even take part in it.

Nomuras are renowned for their grace and beauty. When one swims through the water, it looks like a shimmering aqua ribbon. Nomuras can often be found hiding amongst the coral on a mendota's shell, hitching a ride to new waters. Other than mendota, their magi, and their prey, however, nomuras are shy and hide from all other creatures. To aid them in this, they have the ability to disperse their bodies into water if they feel threatened. They also have the ability to turn any living creature they touch into water. It is believed that this power is used by nomura parents to protect their offspring, as young nomuras cannot use this power. During the breeding season, males show off for females by creating a show of sparkling water, twisting and turning in beautiful patterns. This water looks as if it is filled with fine crystals which reflect the light in a dizzying array of blues and greens.